Radio receiver sequence tuner



MEME? Nov., 9v E948. A. BLAHN RADIO RECEIVER SEQUENCE TUNER 4Sheets-Sheet 2 Filed. April 24. l19E@ INVENTOR mm BLA/lv AENEY mganga-SEE, www QM NWO S99 t. A. BLAHN 2,45%@87 RADIO RECEIVER SEQUENCETUNER Filed April 24 1946 4 Sheets-Sheet 5 w l l n m ATTORNEV Nav., 9,1934.

.1 A. BLMN RADIO RECEIVER SEQUENCE TUNER 4 Sheets-Sheet 4 Filed April24, 194e Z WM uNvENToR ALE/27' BMM! Patented Nov. 9, 1948 RADIO RECEIVERSEQUENCE TUNER Albert Blain, Philadelphia, Pa., assignor to RadioCorporation of America, a corporation oi Dela- Application April 24,1946, Serial No. 664,475

(Cl. 'i4-l0) 14 Claims.

The present invention more particularly lto an automatic tuner of thesequence type in which a series of predetermined broadcasting stationsto which the tuner is adjustably set in advance are successively andautomatically tuned-in by actuation of a single control switch.

One of the objects of the invention is to provide a relatively simple,compact tuner of the type above mentioned which, although not limitedthereto, is capable of usein automobile receivers because of itscompactness and also because its v source of operating energy may be thecar battery or other low-voltage source.

A further object of the invention is to provide a rotatable turret ofnovel design which serves as the position-determining mechanism for thereceiver tuning elements, and novel means for effecting a stepbysteprotation of the turret during each cycle of operation of the tuner.

A still further object of the invention is to provide amanually-operated device in conjunction with the turret which is adaptedto serve both as a manual tuning means for the receiver and as theadjusting means for setting-up in advance the broadcasting stationsdesired to be automatically tuned-in.

These and other objects of the invention and the various features anddetails of the construction and operation thereof are hereinafter fullyset forth and described and shown in the accompanying drawings, inwhich:

Fig. 1 is a plan view, partly broken away, of the tuner according to theinvention;

Fig. 2 is a view, in front elevation, of the tuner shown in Fig. 1;

Fig. 3 is a bottom view of Fig. 1;

Fig. 4 is a view, in cross-section land on an enlarged scale, of theturret assembly;

Fig. 5 is an end view of Fig. 4 looking from the right in Fig. 4;

Fig. 6 is a cross-sectional view taken on the line VI-VI in Fig. 4;

Figs. 7A and 7B are plan views of the cam-slot used to explain themanner in which the step-bystep rotation of the turret is obtained;

Fig. 8 is Ia cross-sectional View, taken on the line VIII-VIII in Fig.2, showing the relative arrangement of such parts, as the actuatingsolenoid, core-carriage bracket and turret assembly, at the beginning ofa cycle of operation, and showing also the turret in the manual tuningposition;

Fig. 9 is a view similar to Fig. 8 showing the mechanism at a point inthe cycle of operation at relates generally to automatic tuningmechanism for radio receivers, and

which the turret and the core assembly are at their respective limits oftravel in the rearward direction;

Fig. 10 is an end view, partly in section, of the solenoid frameassembly, the section being taken on the line X-X of Fig. 8;

Figs. 11 and 12 are views of only the right-hand end of thecore-carriage, Fig. 11 being a plan view and Fig. 12 being a view infront elevation; and

Fig. 13 is a view in cross-section and on an enlarged scale, of themanual tuning device.

Brieiiy, the sequence tuning mechanism of the invention consists of aslidable carriage to which the tuning element (or elements) of aradio'receiver is attached, a multi-position rotatable turret providedwith a plurality of axially-adjustable stops, one for each turretposition, and actuating mechanism which, upon each operation thereof,actuates the tuning-element carriage and the turretin timed relation sothat first the carriage is withdrawn from the turret-stop which waseiective at a previous tuning-in operation, after which the turret isstepped to the next angular position to bring the stop correspondingthereto into operative position, and thereafter the carriage is returnedto abut against said latter stop, whereat the tuning element (orelements) is adjustably set to tune the receiver to a new predeterminedcarrier-frequency.

According to the present embodiment the turret is capable of angularadjustment to six positions, five of which are utilized to automaticallytune the receiver to predetermined carrier-frequencies assigned to thestations which are most frequently heard, and the sixth position isutilized to effect tuning of the receiver through its entire range bymeans of a manual tuning control member arranged to cooperate .with theturret-stop corresponding to said sixth turret position. A solenoidunder control of a m-anually-operated switch is the actuating means forcausing, with the aid of a specially shaped cam-slot, rotation of theturret to successive positions of angular adjustment.

rear bracket 5 and journalled respectively in aligned holes and i formedtherein is a shaft 8 on which a core carriage. shown generally at 9, isadapted to slide. A second shaft I disposed in parallel to shaft 8 hasits forward end journalled in a bushing l I carried by the front plateand its rear end journalled in a hole i2 formed in rear bracket ES. Theshaft l0 at its forward end carries a turret, shown generally at i3,and.

both the shaft and turret are capable of limited axial movement for apurpose hereinafter to be described.

The tuning element ofthe receiver, shown here as of the type known as apermeability tuner, comprises a plurality of tuning coils (not shown),each housed in a shield can M, and a plurality of magnetic cores i5,each movable rwithin its respective coil, the axial adjustment of thecores with respect to their coils determining the tuning adjustment ofthe receiver. The several shield cans ld are suitably supported on adepending bracket l5 fastened lto frame l at its rear edge, said bracketi5 also supporting a number of trimmer condensers i? on tabs i3extending at right angles from the main body of bracket l 6.

The core carriage 9, previously mentioned, is provided with a transversemember i9 to which the magnetic tuning cores l5 are attached through themedium of connecting wires 2@ and adjusting screws 2i (Fig. 3). Thetransverse carriage member is is provided at the right (Figs. l and 3)with a bracket 22 which is mounted for sliding movement on shaft 8, Iandsaid member is is provided at the left (Fig. 2) with a slit or groove 23which is adapted to receive a ledge 2s of a bracket 25 amxed -to theunderside of frame mem- Iber l, the ledge 2d and shaft e serving as apair of rails on which the core supporting carriage is adapted to bereciprocated. A tension spring 2S, attached at one end to front plate@and at the other end to a part of the carriage side-bracket 22, servesto urge the carri-age in a forward direction, the position shown in Fig.1.

In order that the assembly of the slidalblle car riage and tun-ing coresmay be stopped automatically at predetermined lpositions of adjustment,the turret i3, previously mentioned, is provided. The turret i3 and itsshaft I0 are shown in detail in Figs. 4, 5 and 6. On the shaft, betweena pair of nuts 2l and 28 which are threaded on the shaft in spacedrelation, is mounted a guide member 29 provided with six equi-angularlyspaced grooves 3B which extend in the direction of the shaft. Theopposite ends of the guide at 3| and 3|' are of reduced diameter toprovide bearing surfaces for front and rear end-plates 32 and 33. Asshown in Fig. 6, one of the grooves designated 30a is undercut below theothers and, unlike the others, extends through the end bearing surfaces3| and 3 I to provide key-ways which are adapted to receive locking keys34 and 35 formed on the end-plates 32 and 33, respectively, to preventrotation thereof with respect to the guide mem-` ber.

Extending between the two end plates 32, 33 and equi-angularly spacednear their peripheries are six lead screws 36A to 36E and 36M which areprovided each at its rear end with a reduced bearing portion 31journalled within a hole 38 formed 'in the rear end-plate. The leadscrews are provided at their forward ends with heads 39A to 39E and 39M,respectively, which extend through and are journalled at their baseswithin holes lwithin its groove.

d d'0 formed in the front end-plate. A spring plate 42 also keyed to theguide member 29 at its rear end is clamped at the center [between nut-28 and rear end-plate 33. The spring plate is provided with sixradially-extending fingers 43 which coact each with the bearing portion3l of -a 'lead screw to spring-press the same in a forward direction.The screw heads 39 are provided Wi-th radial slots fili adapted to beengaged by a manually-operated key, later to Ibe described, and all thescrew heads are of the same lengthexcept the one designated 39M utilizedto effect manual tuning which is made somewhat longer.

Threaded on the lead screws lare stop-nuts, designated 5A to 65E and 35Mto correspond with their respective lead screws. In order to permit ofindividuali axial adjustment of the stopnuts, which have theconfiguration shown in Fig. 6, their reduced portions d6 are disposedwithin their respective grooves 3G and 30a in guide member 29 so thatupon rotation of a 'lead screw, its stop-nut is restrained from rotationwith respect to the lead-screw ibut is permitted to move axially Fittedover the several screws at the rear -thereof are tubular libre spacersdi which are adapted to limit the range of stop-nut adjustment. 'I'hefront plate 32 is also keyed to kthe guide member and is provided aroundits periphery with six equi-angularly spaced projec-y and are of thesame length except the one designated 48M which-is made longer for apurpose hereinafter to lbe explained. In assembling the turret, thefront plate 32 is keyed in position on the turret shaft so that thelonger projection 48M is disposed diametrically opposite the longerscrew head 39M, and the remaining projections 48A to 68E are similarlydisposed diametrically opposite -their correspondingly numbered screwheads 39A to 39E.

During a cyclev of operation, the turret assemfbly as a unit is actuatedrearwardly in an axial direction to a limiting position after which itis returned by spring means in the opposite or forward direction to itsoriginal position of rest. During this rearward and forward travel ofthe turret assembly, the linear movement thereof is converted by meanslater to be described to one of rota-tion through an angle of 60 whichis the angular distance (between the six circularly-arrangedturret-screws, and stop-nuts. To limit the rearward travel of the turretassembly, a stop member -49 is aixed to shaft I0 at a suitable disitancefrom the rear end thereof. The stop mem?. Iber is in the form of ac-washer fitted into a circular groove 50 in the shaft and thereforekeyed thereto, and in coacting with the rear bracket '5 the stop memberlimits rearward travel of the turret assembly. A felt washer 49 isinterposed between C-washer stop I9 and bracket 5 to cushion therearward thrust of the turret assembly. The forward or return travel ofthe turret assembly is brought about by a leaf-spring 5l vengaging ltherear end of the shaft and is limited by the front lock nut 21 coactingwith the Yedge of bushing I I within which the forward end vided at i!with a cut-out or slot of the contiguration shown in Fig. 1, the slotbeing disposed in overlying relation with respect to the front end ofthe turret. The slot, shown in plan in Fig. 1;

is shown in Figs. 7A and,7B enlarged to about twice its actual size. Theslot is Y-shaped, having a center. part 63 which extends in a directionparallel to the turret shaft, a pair of side parts M and 5l whichemanate rearwardly from part Il, and a pair of substantially rectangularparts il and i1 in which the parts 54 and 55 terminate,

adjacent plate projections 48A at the left and, f

E at the right, will then appear underneath `the frame I in theirrespective dotted-line posi tions as shown. During the initial rearwardmotion of the turret assembly and until projection 48M reaches theposition indicated at 48Mi whereat is coacts with the upper edge 54 ofthe slot part 64, there is no rotation of the turret. The correspondingpositions for the adjacent projections are indicated at 18A- i and48E-l. As the turret assembly continues to move rearwardly, theprojection 48M is constrained to move along the upper edge 54' until itreaches the position indicated at 48M-2. During this portion of therearward travel of the turret, the slot edge B4' acts to cam the turretin a clockwise direction through 30. Simultaneously, the adjacentprojection 48A at the left is moved where it just enters and protrudesthrough the terminal slot part 5l, and the other adjacent projection 48Eat the right is moved away from the right-hand terminal slot 563.

Shortly thereafter stop-member it on the turret shaft coacts with feltwasher 49' and bracket E5 at which time the turret assembly reaches itslimit of travel in the rearward direction, and the actuating force formoving the turret is made ineffective. Spring 5l which was flexed duringthe rearward travel of the turret now acts to urge the turret in aforward direction. The projection dBA at the left now begins to movefrom its position at AdA-2 in Fig. 7A to the position indicated at 8A-3in Fig. 7B. Simultaneously the projection 38M moves from its positionindicated at BM-i in Fig. 7A. to the position indicated at GBM-3 in Fig.7B. At the position @GA-3 for vprojection 48A, the latter begins tocoact with the lower edge of the slot part 55 and during the course oftravel of projection 48A from this latter position to the positionindicated at dBA-55. the slot edge 55 acts to cam the turret in aclockwise direction through a further 30 rotation. During the final partof forward travel of the turret assembly, the projection 48A will droptowards the front part of the center slot 53 where it comes to rest,replacing the projection 48M Since the turret-rotating projections movein a circle about the turret shaft as -a center, the portion of theframe surrounding thecam slot, between the terminal parts 58 and l1, ismade arcuate as shown at ll in Fig. 2 in order to accommodate first thearcuate travel of one Drojection through the cam-slot part M and thenthe arcuate travel of the next projection through the cam slot part 55.

The sole actuating device for the tuning mechanism is a solenoidmechanism, the functions of which are to drive the turret'from itsforward rest position to its rear limiting position as described above,and to move the tuning-core carriage-also 'from a rest position Ato alimiting position. The solenoid, shown generally atin Figs. 2 and 8, issupported at the `lower end of a bracket 8l, below and in parallelismwith the turret, and the upper end 82 of the bracket is attached to theunderside of the frame I at 62' (Figs. 8 and 9).

i The solenoid (see Fig. 8) consists of a coil 83 wound on -a sleeve 84,a tapered core. 65 extending into the sleeve at the left, and anarmature or plunger movably mounted within the sleeve at the right. Thecore is threaded at 5l and a locknut 68 screwed thereon is adapted tomaintain the kcore in an axially adjusted position within the coil. Themovable armature or plunger on the side facing the core is provided witha conical bore 86' so that when the plunger is actuated to the left itwill seat itself on the conical end of core 65. The armature 66 at theright is provided with a reduced portion69 which is adapted to receive,between a pair of grommets-'19, the forked end 'H of a bracket 12. Thisbracket consists of a center part 13, an arm ld provided with the abovementioned forked end li turned downwardly at right angles to the centerpart at one-end, and an arm l5 provided 'with a second forked end 18turned upwardly at right angles to the center part at the other end. Thebracket arm l5 is provided with an aperture il through which therepasses a shaft 'IB supported between a pair of ears 'ld which extendfrom the bracket 6i at right angles thereto. .d coil spring t@ isdisposed between the ear l@ at the left and the bracket arm l5 in orderto urge the armature @d to the right, externally of the solenoid coil,when the solenoid is deenergized. In order to provide true linear motionfor the armature dii and the bracket 'it afxed thereto, there isattached to the center part V3, by spot-welding or otherwise, a memberiii having; an apertured upstanding part 82 through which the shaft litiextends. thereby providing a double suspension on shaft' 'i8 for thearmature carrying bracket it. The forked end 'it of bracket arm l5 isadapted to engage the turret shaft i@ to the rear of' the turretclamping nut 2t (Figs. 4 and d), and disposed on the shaft betweenbracket arm i@ and the C-washer stop 49, in the order named, are a feitwasher 83, the forked' end @d ci. a bracket amxed to the carriage sidebracket t2, a second felt washer 85 and aV metal washer 85 (Figs. d and8). As best seen in Figs. 1l and l2 the carriage side bracket 22 hasattached to it at its forward end a bracket l1 having an arm 88 bent atright angles, with the bifurcationl 8B above-mentioned formed at the endof said arm.

Upon energization of the solenoid Bil, by the closure of a switch 89(Fig. 1) under the control of a manually-operated member, such as apushbutton 90, which may extend through thefront panel 8i of thereceiver or be carried on the steering wheel in the case of-areceiverinstalled in an automobile, its armature $6 is pulled in tothereby actuate the forked end 16 of the bracket 12 rearwardly or to thelef-t as viewed in Figs. 4 and 8. This actuation causes the rearwardtravel of the core carriage 9 by reason of the coaction between saidforked end 16 and the forked end 84 of the carriage bracket 81, andcauses also the rearward travel of the turret by reason of the coactionbetween the rearwardly driven forked end 84 and the group of washers 85,86 and 49. The relative positions of said driving and driven forked arms16 and B4, respectively, and the turret stop 49, at the beginning of vacycle of operation, are shown in Fig. 8. In Fig; 9 the solenoid armatureis shown at the end of its stroke, and the turret assembly and thedriven forked arm 34 for the, core-carriage are shown .in theirrespective limitingpositions. In this state of the mechanism the tuningcores l are in their fully entered position with respect to their coils.

In order that the core-carriage may be stopped at a predeterminedposition corresponding to the angular adjustment of the turret, thecarriage side-bracket 22 is provided with a plate member 92 whichextends horizontally, underneath the turret and -tangentlally thereto(Figs. 3, 11 and 12). Afxed to the upper surface of member 92, as byrivets 93, is a stop plate 94, the forward end of which overhangs theforward end of the supporting plate 92. In order to prevent relativeshift between the stop plate and its supporting plate, the rear end ofthe former abuts against a raised protrusion 95 formed in the latter. Ina setl position of Ithe turret (see Figs. 3 and 8) the lowermost stopnut, 45A in Fig. 3 and 45M in Fig. 8, is the one with which the stopplate 94 coacts and which is effective to stop the core-carriage andtuning element at a predetermined position of adjustment.

From the preceding description it is believed that the operation of thetuning mechanism of the invention will be clear. However, in the way ofsummarizing, the following brief explanation of a complete cycle ofoperation will be given. It is assumed that at the beginning of thiscycle of operation, the turret is in the angular position shown in Figs.4, 5 and 8, which is the position to which the turret was set in theprevious cycle and in which the stop-nut 45M was eiective. To initiateoperation of the tuner to eilect its adjustment to the next position inthe sequence in which the several predetermined stations are adapted tobe tuned-in, push-button 90 (or its equivalent) is actuated to closeswitch 89 for the purpose of energizing solenoid 60. As a resultarmature 66 is pulled into the solenoid, winding 63 against the actionof spring 80, and the solenoid bracket 12 is thereby actuatedrearwardly, carrying along withl it the core-carriage 9 and the turretI3. The first to move is the core-carriage to bring about thedisengagement between stop-plate 94 and the stop-nut 45M. After a shortinterval, the time that it takes for forked arm 1B to actuate forkedyarml 84 from its rest position to the position occupied by the stopwasher group 49, 86 and 85, the turret begins to move rearwardly andcontinues to do so until stopped vby coaction of stop washer 49 againstwasher 49. At this instant the core-carriage is in its most rearwardposition, whereat the tuning cores are fully entered in their respectivecoils, and thev turret is in i-ts most rearward position. As heretoforeexplained in connection with Figs.

1A and 7B, the turret is rotated through 30 in a clockwise directionduring the courseof its rearward travel Ta.

With the solenoid deenergized after the carriage and turret have reachedtheir limiting positions, spring 80 causes the returnv of the armaturebracket 12 to its original forward position 'l (Fig. 8), removingthereby the driving force for the turret and core-carriage. 'Ihe turretis now permitted to move in a forward direction under the action of leafspring 5I and the carriage is also permitted to move in a forwarddirection under the action of coil spring 26. Since the turret is causedto move through a shorter distance than the core carriage, it willarrive at its forward rest position, after having been rotated throughan additional 30 as previously described, slightly ahead of thecarriage, so lthat the turret will have been moved to its nextsuccessive position in the sequence to present the stop-nut 45A in thepath of forward travel of the carriage stopp'late 94. With the carriagethus returned to its new position whereat it coacts with the stop-nut45A just brought into position, the cycle of operation is completed.

In order to effect manu-al tuning of the receiver, when desired, andalso to make theiinitial individual adjustments of the severalstop-nuts,

vthere is provided a manual tuning and adjusting K device |00, showngenerally in Figs. 1 and 3, for example. and in detail in Fig. 13. Thedevice |00 extends through an aperture |0| formed with-l adapted toreceive a c-washer |09, and betweenV a shoulder H0 at the right of themain shaft b ody I 04 and the C-washer |09 are disposed a washer I, acoil spring I 2, and a second washer |13. The washer |I| is urged byspring |I2 against a shoulder H4 formed on the inner 'surface of thebushing |02 so that by depressing shaft |03 by means of knob |01 theshaft is urged rearwardly against the action of the spring and upon 4therelease of .the tuning knob the spring |I2 tends to return the shaft` toits normal forward position.

At the other side of shaft |03 there is provided a reduced portion I I5which is adapted to receive the apertured end of a hollow housing H6provided with'two diametrically opposed slots H1 within which the sides||8 oi' a' at key I|9 is adapted to be slidably fitted. A coil spring|20 is disposed within the housing between the base portion |2| of thekey and the shaft supported end of the housing to permit relativemovement of the key with respect to the shaft. This relative movement ofthe key is necessary when the turret assembly is being rotated to itsmanual tuning position shown in Fig. 8. Since the key is in the path ofthe longer screw head 39M, it is necessary that the key be free to movein an laxial direction when urged to do so by the screw head until thelatter finally comes to rest when the key will eventually drop into apair of aligned screw head grooves 44 due to the action of coil spring|20.

Iacts with stop-nut 45M.

As heretofore stated the longer projection 48M on the turret front plate32 is disposed` diametrically opposite the longer screw head 39M so thatin the manual tuning position shown in Fig. 8, the projection 48M,extends through the cam-slot 52 and in a position to close a switch |20mounted on the frame i above the turret assembly. This switch closes acircuit for a dial light |26 (see Fig l) locatedibehind an indicatorplate |21 in the front panel 9| to visually indicate that the tuner isset for manual operation.

For the purpose of initially setting-up the various stations to which it.is desired that the tuner be automatically adjusted, the push-button 90is actuated to effect rotation of the turret to any angular position. Inthis turret position the manual tuning shaft |03 is pressed in againstthe action of springs H2 and |20 to force key ||9 to engage the screwhead aligned therewith. The shaft in the depressed position is nowrotated by knob |01 to cause the corresponding stop-nut to be`moved inan axial direction, which in turn causes the core carriage to move. Thetuning knob is thus manipulated until the desired station is received.The knob is then released, and thereafter when the turret is againrotated to the above angular position the receiver will be tuned- `inautomatically to said selected station. The

same procedure as above is followed for the diier. ent angular turretpositions, except that for which manual tuning is employed, so that insubsequent actuations of` the push-button 90, the various selectedstations will be tuned-in automatically and in a predetermined sequence.

f It will be noted from Fig. 4 that the lead screw 36M which serves toeiect manual tuning is shown as having a greater pitched screw-threadthan the other lead screws 36A to E used to efect auto= matic tuning.This is to provide more rapid travel of the carriage-coactingstop-member 45M for rnaifiual` tuning and a relatively slow ormicrometer adjustment of the stop-nuts 45A to E for initially setting upthe stop positions to which the tuner is to be automatically actuated.

A pointer mechanism for indicating the tuning core position, or thefrequency adjustment of the receiver, is shown generally at |36 in Fig.l. 'The mechanism is supported on a bracket |35 attached to the underside of the lframe I. Since this mechanism does not form a part of thepresent invention, further description thereof will not be given exceptto state that actuation thereof is accomplished by means of anupstanding pin |32 mounted on the core carriage and that the linkageemployed in the mechanism for actuating the pivoted pointer arm |33 issuch that the pointer i343 at the end of said arm extending through anclon-gated slot |35 in the front panel 9i of the receiver is caused totravel linearly within said slot in response to linear travel of thecore carriage over its range. In other words. the pointer mechanismfunctions to translate the linear movement of the carriage or tuningelement in one direction to a similar movement of the pointer (lil the

the spirlt and scope of this invention. I therefore contemplate by theappended claims to cover any such modifications as fall within the truespiritv and scope of my invention.

What I claim is:

1. The combination, in radio adjustable tuning element, a rectilinearlymovable carrier for said tuning element, a cylindrical turret providedwith a plurality of circumferentially arranged stops, individuallyadjustable in an axial direction each to a position which' determines aparticular setting to which the tuning element is actuable, said-turretbeing capable of both axial and rotary movements, means operable to movethe tuning element carrier to a limiting position and simultaneously tomove the turret in an axial direction. means including a cam slot,coacting with the turret to convert the axial movement thereof torotary movement whereupon in response to actuatlons of thecarrier-moving means the turret is rotated step-by-step to successivepositions at each of which a stop corresponding to the turret positionis made eil'ective, and means operable to move the tuning elementcarrier from its limiting position to one whereat it coacts with thethen eilective stop as determined 'by the turret position whereby thetuning element is adjusted to the setting 'corresponding to said stop.

2. The combination, in radio apparatus, of an adjustable tuning element,a movable carrier for said tuning element, a turret provided with aplurality of stops, individually adjustable each to a position whichdetermines a particular setting to which the tuning element is actuable,said'turret being capable of both axial and 4rotary movements, meansoperable to move the tuning element carrier to a limiting position andsimultaneously to move the turret in an axial direction, a xed memberspaced Afrom the turret and having a cam slot formed therein, meanscarried by the turret and coacting with the cam slot to convert theaxial movement of the turret to rotary movement whereupon in response toactuations of the carrier-moving means the turret ls rotatedstep-by-step to successive positions at each of which a stopcorresponding to the turret position is made eectlve, and means operableto move the tuning element carrier from its limiting position to onewhereat it coacts with the then eifective stop as determined by theturret position whereby the tuning element is adjusted to the settingcorresponding to said stop.

3. The combination dened in claim 2 wherein the turret is provided witha disk having a piurality of equally-spaced projections equal to thenumber of turret stops disposed around its periphery, said projectionsconstituting the means which coact with the cam slot, and wherein thecam slot is of such configuration that concomitant with axial movementof the turret, coaction of a turret projection within the cam slotcauses rotation of the turret through an angle equal to the angularspacing of the projections.

4. The combination dened in claim 2 wherein the cam slot is Y-shaped andis disposed with its center portion extending in the direction of axialmovement of the turret and with its arm portions converging forwardly.and wherein the turret is apparatus', of an provided with a disk yhavinga plurality of equallyspaced projections equal to the number of turretstops disposed around its periphery, the arrangement being such that ina state of rest, at which time the turret is in its most forwardposition, one of the disk projections extends into the center slotportion at its forward end, and during rearward axial movement of theturret said projection is caused to enter from said center portion intoone of the arm portions to cause partial rotation of the turret, andduring the return axial movement of the turret to its state of rest thenext adjacent projection is caused to enter first into the other armportion and then into the center slot portion to complete the rotationof the turret, the total rotation of the turret being equal to theangular spacing of the turret-disk I projections.

5. The combination dened in claim 2 wherein the cam slot is formed witha linear portion which extends in a direction parallel to the directionof axial movement of the turret and with a pair of forwardly convergingportions which communicate with the linear portion at one end thereof,and wherein'the turret is provided with a disk having a pluralityl ofequally-spaced projections equal to the number of turret stops disposedaround its periphery, the arrangement being such that in a state ofrest, at which time the turret is in its most forward position, one ofthe disk projections extends into the linear slot portion at its forwardend. and during rearward axial movement of the turret said projection iscaused to enter into one of the converging slot portions wherein an edgethereof in coacting with said projection serves to impart rotation tothe turret through a part of its normal rotation, and during 12 ret,occurring after the return of the turretshaft to its normal axialposition, t,

7. The combination, in radio apparatus,.of an adjustable tuning element,a supporting structure, a carrier for said tuning element mounted forlinear movement on said supporting structure,

a turret provided with a plurality of stops, individually adjustable`each to aposition which dethe return axial movement of the turret to its4 state of rest the next adjacent projection is caused to enter into theother converging slot portion wherein an edge of the latter portion incoacting with said next projection serves to impart rotation to theturret through the remaining part of its normal rotation, the angularspacing of the disk projections constituting the normal rotation of theturret.

6. The combination, in radio apparatus, `of an adjustable tuningelement, a supporting structure. a carrier for said tuning elementmounted for linear movement on said supporting structure. lamulti-position rotatable turret the angular posi'- tion of whichdetermines the particular setting to which the tuning element isactuable, a shaft on which the turret is mounted arranged for axial androtary movement, a stop member on the shaft cooperatively engageablewith said supporting structure for limiting the axial movement of theIshaft and turret, a bracket aflixed to the carrier mounted for causinglinear movement of the turret shaft, actuating mechanism for the carrierand turret having a reciprocable member also mounted on the turretshaft, said reciprocable member, upon operation of the actuatingmechanism to drive said member to its llimiting position, arranged toactuate the tuning element carrier and turret shaft to their respectivelimiting positions, means for effecting individual travelof--thereciprocable member, tuning element carrier and turret shaft away fromtheir respective limiting positions, and means cooperating with theturret for imparting rotary motion thereto during axial travel of theturret shaft in both directions, the return of the tuning elementcarrier to its new position of adjustment, as

determined by the rotary adjustment 0f the @111'- termines a particularsetting to which the tuning element is actuable, a shaft on which the,-

turret is mounted arranged for axial and rotary movement, a stop memberon the shaft cooperatively engageable with said supporting structure forlimiting the axial movement of the shaft and turret, a bracket amxed tothe carrier mounted for causing linear movement of the turret shaft,actuating mechanism for the carrier and turret having a reciprocablemember also mounted on the turret shaft, said reciprocable member, uponoperation of the actuating mechanism, arranged to travel in a directionfrom its normal position to a limiting position against the action of aspring which, upon the actuating mechanism becoming inoperative, causesthe return of said member in the opposite direction to said normalposition, said reciprocable member during rits travel in said firstdirection acting first to engage the carrier bracket to move the carrieragainst the action of the spring to its limit of travel and later toengage the stop member on the turret shaft to move the latter from itsnormal position to a limiting position against the action of a spring,the return of the turret shaft by its spring to its normal positionoccurring during the first part of the return travel of the reciprocablemember, and means cooperating with the turret for imparting rotarymotion thereto during the axial travl of the turret shaft in bothdirections, the return of the tuning element carrier by its spring toits new position of adjustment,

' as determined by the rotary adjustment of the turret, occurring afterthe return of the turret shaft to its normal axial position.

8. The combination, in radio apparatus, of an adjustable tuning element,a reciprocable carrier for said tuning element, a multi-positionrotatable turret provided with a plurality of stops, one for each turretposition, said stops being individuallyadjustable axially of the turreteach to a position which determines a particular setting to which thetuning element is actuable, actuat- K ing mechanism operable upon eachactuation to withdraw the carrier from a previously adjusted setting andto impart linear motion to the turret, means including a cam slot forconverting the linear motion of the turret to rotary motion wherebyv theturret is stepped to a position whereat the corresponding stop is madee'ective, and means operable to return the tuning element carrier toabut against the said effective stop whereby the tuning element isadjusted to the setting corresponding to said stop.

9. The combination defined in claim 8 wherein the turret is providedwith a plurality of equiangularly arranged projections, one for eachturret position, and said projections cooperating successively with thecam slot to effect the stepby-step rotation of the turret.

10. The combination, in radio apparatus, of an adjustable tuningelement, a movable carrier for said tuning element, a turret providedwith a plurality of equi-angularly arranged stops, individuallyadjustable axially each to a position which determines a particularsetting to which the tuning element is actuable, said turret being 13capable of both axial and rotary movements, means operable to move thetuning-element carrier to a limiting position and simultaneously to movethe turret in an axial direction, a fixed member spaced from the turretand having a cam slot formed therein, a plurality of equi-angularlyarranged projections carried by the turret, said tion to one whereat itcoacts with the then effective stop whereby the tuning element isadjusted to the setting corresponding to said stop.

11. The combination deined in claim 10 wherein the turret has apredetermined angular position at which the tuning element is actuableby manual means, 'and a switch is provided in circuit with a dial lightwhich serves as a visual indicator for said manual tuning position, saiddial-light circuit-switch adapted to be closedby one of the turretprojections.

12. The combination defined in' claim 10 wherein one of the turretprojections is longer than the others and the turret has a predeterminedangular position at which the tuning element is actuable by manualmeans. and a switch in circuit with a dial light serving as a visualindicator for said manual tuning position operable by said longerprojection to close said dial-light circuit-switch.

13. The combination defined in claim 10 wherein the tuning-element stopsare threaded each on a lead-screw provided with a screw-head at one end,and the stop which is effective for any turret position is diametricallyopposite to the proiection which for that turret lposition is locatedwithin the cam slot, and a device for adjusting device comprising amanually-operable shaft which for any adjusted position of the turret isaxially aligned with the lead-screw the stop of which is effective toposition the tuning element,l and a key at the end of said shaftnormally spaced from the screw-head of the aligned lead-screw andadapted to interlock therewith when the shaft is pushed'in and to rotatethe lead-screw when the shaft is rotated.

14. The combination defined in claim 10 wherein the tuning-element stopsare threaded each on a lead-screw having -a screw-head at one end, oneoi said lead screws having va greater pitched thread' than the others toprovide a more rapid travel of the associated stop, a device foradjusting lthe respective axial positions of the several tuning-elementstops comprising a manually-operable shaft, the angular setting of theturret at which said greater pitched lead-screw and manually-operableshaft are aligned serving as the manual tuning position of theapparatus, the screw-head at the end of said greater pitched lead-screwbeing longer than the others and just long enough to interlock with thekey in the normal shaft position, the radial turret projection whichcooperates with the-cam slot at the manual tuning setting of the turret.being longer than the others and a switch located above the cam slotadapted to be closed by said longer turretpro- Jectlon, said switchbeing included in a circuit for the dial light which serves as a visualindicator for said manual tuning setting.

ALBERT BLAIN.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number Name 4 Date 2,310,720 Wandrey Feb. 9, 19432,342,691 Plensler Feb. 29, 1944

